Railway signaling and train-control system



1. A. MILLER, RAILWAY SIGNALING AND TRAIN'CDNTHOI. SYSTEM, APPLICATION FILED FEB- 21, I9I9- RENEWED MAY 6.1922- 1,419,289. I Patented June 13, .1922.

1 UNITED STATES v PATENT OFFICE.

JOHN A. MILLER, OF LOS ANGELES, CALIFORNIA, ASSIGNOR '10 LAURENCE It.

WILDER, OF CHICAGO, ILLINOIS.

RAILWAY SIGNALING AND TRAIN-C(INTROL SYSTEM.

Specification of Letters Patent. Patented June 13, 1922.

Application filed February 21, 1919, Serial No. 278,425. Renewed May 6, 1922. Serial No. 559,060.

stated contemplates a system for indicating conditions of danger and safety along the right-of-way. through the medium of electrical devices controlled or operated by high frequency currents. The specific embodiment of my inventiin hereinafter described in detail is particularly adapted for use in connection with gauntlets and crossovers in connection with double track operation. However, notwithstanding the factthat the specific arrangements of circuits and apparatus herein shown and described are admirably suited for providing the necessary indications of safety and danger conditions at or near gauntlets and cross overs as just explained, I wish to have it understood that my invention is in no way so limited.

Inasmuch as the description and explanation of my present invention will be best understood when read in connection with the drawing illustrating a practical embodiment thereof, I shall proceed at once to a description of the accompanyin drawing, which more or less diagrammatically illustrates my invention applied to an electric railway system.

In the drawing I have illustrated an electric railway which may be regarded as a double track system, although at one portion it comprises a single track or gauntlet section, illustrated at C, which is designed to carry all of the traffic, both eastand west bound, between the points at which the gauntlet connects with the double tracks at either end thereof. In the drawings I have illustrated the sections of the west bound track which connect with the gauntlet C at A and A, and the sections of the east bound track connecting with the gauntlet at l) and B. Straight track sections corrcspmnling to the section C shown in the drawing, which I have referred to as a gauntlet, are well known in railway practice and are quite commonly used in passing over bridges, through tunnels, etc.

At 1 I have illustrated the trolley wire used in connection with the system just described, it being noted that the trolley is divided into the gauntlet section 0, the sections a and b for the double track A and B at the left or west end of the gauntlet C, and the sections a and b for the double track sections A and B at the right or east end of the gauntlet.

While I have not illustrated the feeders for the trolley wire 1, it will suflice to say that the said trolley wire, generally indicated by the reference character 1, is supplied with propulsion 'current from suitable generators through feeders (not shown). I

will point out at this time that the gauntlet section 0 of the trolley wire is separated'at the west end thereof from the trolley sec tions at and b and at the east end thereof from the trolley wire sections a and b by suitable insulated joints 2-2, suitable inductive impedance bonds 3- 3 serving to carry the direct propulsion current around the insulated joints 2, but serving to prevent the passage of the high frequency currents. which will be more fully referred to as this description progresses.

Referring now to the left side of the drawing, it will be seen that at 4 I have illustrated a motor generator set, the motor- .of which is connected .between the trolley wire section b and the track, suitable inductive and non-inductive resistances 5 and 6 being included in series with the motor to prevent the passage of high frequency oscillatory currents, and to regulate the direct current supply to the motor of the said motor generator set 4. The terminals of the generator of the motor generator set 4 are connected with the primary of a loose coupled transformer 7 the secondary of which is electrically connected with a spark gap generator of high frequency oscillatory currents, of which 8 indicates the spark gap, 9 the condensers, and 10 the helix. tors of this type are generally known, wherefore a detailed description of the same is considered unnecessary. It will suflice to say that the high frequency generator just described and which I may refer to as a whole by the reference letter D, is designed to Generasupply oscillatory current of a frequency of substantially ten thousand to the gauntlet section a of the trolley wire, one terminal of the helix being connected by conductor 11 with the gauntlet section 0 of the trolley wire, and the other terminal of the helix being connected b conductor 12 with the track section of t e gauntlet C. Interposed in the conductor 12 is a condenser 13 and a manually or mechanically operated switch 14. It will suffice to say that the function of the condenser 13 is to prevent the passage of propulsion current through conductors 11 and 12 from the trolley section 0 to the gauntlet track section C, without, however, interfering with the generation of the high frequency current of ten thousand frequency supplied by the spark gap generator D. The purpose and function of the switch 14 will be referred to later. It may be well to point out at this time that the conductor 11 connects with the trolley wire section 0 of the gauntlet at or near the left or west end thereof.

The right or east end of the gauntlet trolley wire section 0 is supplied with oscillatory current of a frequency of substantially five thousand, through conductor 11, from the spark gap generator of high frequency oscillatory currents E, similar in all respects to the generator D hereinbefore referred to, save in the arrangements and adjustments which render the generator E capable of generating the current having a frequency of five thousand, in contra-distinction to the current having a frequency of ten thousand supplied by the generator D. The circuit arrangements used in connection with the generator E for completing the high frequency circuit, and for exciting the enerator E are substantially identical with the circuit arrangements employed in connection with the generator D, and it will be unnecessary to describe in detail the several conductors and instrumentalities used in connection with generator E, which correspond with those employed in connection with generator D. It will sufiice to say that conductors and devices used in connection with generator E, corresponding to those used with generator D, have had applied thereto the'same reference numerals primed.

From the description above it follows that normally the generator D is impressing an oscillatory current having a frequency of substantiallyten thousand upon the left or west end of the gauntlet trolley wire section 0, whereas the generator E is, impressing an oscillatory current of substantially five thousand frequency upon the east end of said trolley wlre section 0.

Referring now to the left side of the drawing, it will be noted that at F I have illustrated a branch circuit, including adjustable condenser 15 and inductive resistance 16,

which connects the left end of the gauntlet trolley wire section 0 with the trolley wire sections a and b, and constituting a path for oscillatory current of five thousand frequency around the insulated trolley wire break 2, the capacity and inductance of the branch F being so adjusted as to tune the latter and permit the passage of current ofa five thousand fre uency, as just explained; the current of ten t ousand frequency being excluded from F. I contemplate utilizing the high frequency current traversing the branch circuit F, to energize a suitable s1gnal, and in the drawing I have illustrated as to capacity and inductance as to be in tune with and permit the passage of current having a-frequency of ten thousand.

will now proceed to describe the circuits and apparatus carried by cars movable over the railway in question. In the center of the drawing I have diagrammatically indicated at H a. car provided with a trolley 18 and with wheels. Propulsion current is supplied through trolley 18 and conductor 19, in

which may be included a suitable inductive resistance 20, to panel board or cut-out box 21, thence through conductor 22 to controller 23, and thence to the motor (not shown) and the wheels, in theusual manner. Connected in shunt of the inductive resistance 20 is a branch 24, including the primaries of loose couple transformers 24 and 25. The secondaries of the adjustable tuning trans formers 24 and. 25 are connected with and in effect form a part of oscillatory current detectors I and J, the detector I being tuned to a frequency of five thousand and the detector J to a frequency of ten thousand. The detectors are conveniently of the ordinary Pliotron type, embodying the Pliotron valves 26 and 26 connected with the usual local batteries and condensers, and connected in circuit with the secondaries of the tuning transformers 24 and 25. It will be seen that the detector I is connected with a relay 27, provided with an armature 28, the detector J being provided with corresponding relay and armature, indicated respectively at 27' and 28. Thus, when the high frequency oscillatory current of five thousand frequency is supplied through the trolley 18, the detector I effects the energization of the relay 27, and thereby attracts the armature 28.to lie against its front contact, and correspondingly, when high frequency oscillatory current of ten thousand frequency is supplied through the trolley 18 the detector J effects the energization of the relay 27 and causes the attraction of the armature 28 of the latter. It will be seen that armatures 28 and 28' are arranged to control the cir cuits for suitable signal lamps 29 and 30, which in practice are mounted so as to be readily visible to the motorman or engineer, as the case may be. The lamps 29 and 30, of which 29 preferably has a green bulb and 30 a red bulb, are connected in circuit with a storage battery 31, and the circuit arrangement for the lamps 29 and 30 is such that when either the armature 28 or the armature 28 lies against its front contact, the circuit for the reen lamp 29 is closed, and when either of the armatures liesagainst its back contact, the circuit for the red lamp 30 is closed. Included in series with the armatures 28 and 28 are the switches 32 and 33,

the arrangement being such that when either of the switches is open, its corresponding relay armature is incapable of closing the circuit of either of the lamps 29 and 30. In practice the switches 32 and 33 are designed to be mounted so as to be accessible to the driver, the switch 32 being closed when the Car is traveling east, and the switch 33 closed when the car is traveling west.

I find it desirable to provide means for insuring that whenever the electrical connection from the trolley wire to the car is broken, through removal of the trolley from the wire,.through accident or otherwise, high frequency currents which may be traversing the trolle wire shall be available for detection by t e detectors I and J and to that end I provide an expansible electricity con ducting framework comprising the arms 34, 34, one endof each of said arms being pivoted to the top ofthe car and the other end pivoted to one of the arms 35, 35, springs being provided at the points where the arms 34 and 35 are pivotally connected, tending to extend the framework. The arms 35, 35 are pivotally connected to each other and carry a horizontal electricity conducting bar or arm 36, arranged to make electrical connection with the trolley wire when the framework is extended. The framework just referred to is normally held in lowered or depressed position by a latch 37 engaging in a notch in the lower end of an arm 38, depending from the top of the said framework, the said latch 37 being provided with a spring 39 which tends to disengage the latch from the arm 38, said latch 37 however, normally being held in locking position by a magnet 40, the said magnet 40 being. included in a shunt from the conductor 19 to the wheels, which shunt includes a non-inductive resistance 41 so adjusted as to permit suflicient direct current to pass through the magnet winding 40 to hold the armature latch 37 in locking position when the trolley 18 is in engagement with the trolley wire, the resistance 41, of course, being sufficiently high to prevent a substantialshort circuit of the propulsion current. By virtue of the arrangement just described, when the trolley 18 isin contact with the trolley wire, the latch 37 is heldin locking position and the framework just described is locked in lowered position, but should the trolley be disengaged from the trolley wire, accidentally or otherwise, de-energization of the magnet winding 40 permits the release of the latch 37, whereupon the springs at the junctions between the arms 34 and 35 of the framework cause the extension of the framework, and the bar or arm 36 is brought into engagement. with the trolley and provides a path for high frequency currents through the bar 36 and framework, conductor 42, conductor 19, and branch circuit 24 and the shunt including the magnet winding 40 and resistance 41.

Having now described in more or less delot) may be assumed that the signaling devices are provided solely for the purpose of indi' cating conditions of safety or danger in or adjacent to the gauntlet. In fact,'in practice it is oftentimes considered important to provide signaling devices for clearly and unmistakably indicating conditions of danger and safety at points such as gauntlets. cross-overs and the like, whereas in such cases it may not be considered so necessary or desirable to have the rest of the right of way thus protected. Therefore, in considering the present embodiment of my invention, wemay assume that the signaling devices on the car are madeuse of only between certain limits, say a half mile, on each side of the gauntlet.

We will assume that for travel outside of the limits just mentioned, the switches 32 and 33 are opened and that one of them is always closed whenever the car enters the said limits, switch 32 being closed in case the ear is east bound, and the switch 33 closed in case the car is west bound. Although in a system of the class described the switches may be either manually or automatically closed when the car enters the aforesaid limits, I have for clearness illustrated merely manually operated switches.

Now let us assume that the gauntlet is clear and there is an east bound car approaching the gauntlet on the track section B. The oscillatory current of five thousand frequency applied to the gauntlet trolley wire section 0 traverses the shunt F and causes the lighting of lamp 17, which being located along the right of way at or near the west end of the gauntlet indicates that the gauntlet is clear.

'As soon as the approaching east bound car passes within the limits previously mentioned and its switch 32 has been closed, as just explained, the current of five thousand frequency applied to trolley wire section I) through the shunt F finds a path through the trolley of the car in question and passes.

through its branch circuit 24 due to the socalled instantaneous potential difference between the points at which the branch circuit 24 connects with conductor 19, and thence to the wheels through either the propulsion motor circuit or the shunt including the electromagnet 40 and resistance 41, or through both of these paths. I

The high frequency oscillatory current thu's traced through the circuits mentioned being detected by the detector I results in the energization of the magnet 27 and the attraction of the armature 28, with the result that the circuit forthe green lamp 29 is closed and the lamp lighted visually indicating that the gauntlet is clear and that there is no east bound car betweenithe' gauntlet and the car under consideration;

' In the case of a west bound car approach.- lng the gauntlet with latter clear, the operation of the signaling devices would be substantially thesame except thatin this case the switch 33 would be closed and the switch 32 open, and it would be the energization of the relay 27 through the detector J, responsive to current of ten thousand frequency that would cause the closing of the circuit of green lamp 29.

Now let us assume that there is a car in the gauntlet as illustrated in the drawings. The high frequency oscillatory currents supplied by both generator D and generator E find paths through the car circuits to the rails with the result that no high frequency current, or substantially none, passes through the trolley wire shunts F and G, with the result that lamps 17 and 17 remain unlighted and safety conditions are not indicated at these points, for I have found that the high frequency currents in these cases will find a path through the car circuits rather than to take a longer path or path of greater impedance. Thus with a car in the gauntlet and cars approaching the gauntlet from one or both directions, the lamp 17 and 17 (indicating safety) would not only be unlighted but neither of the approaching cars would receive any high frequency current with the result that their respective red lamps 30 would be lighted, indicating it to be unsafe to proceed into the gauntlet.

In the case of two cars approaching a clear gauntlet from the same direction, both within the fixed limit at which the car signals are designed to be used, the first car would receive a safety indication due to the response of its proper detector (I in the case of an east bound car and J in the case of a west bound car), to the proper high frequency current, and the consequent lighting of its green lamp 29, but the second car would receive no high frequency current due to the same being diverted through the circuits of the first car, with the result that the red lamp 30 of the second car would be lighted. Furthermore, the red light of the second car will continue to indicate danger until the first car has passed through the gauntlet and thus enabled the proper high frequency current to become operative upon the signal circuit of what was formerly the car behind.

To prevent the possibility of cars from opposite directions entering the gauntlet at the same time, I provide the switches 14 and 14:. A. trainman of a car about to enter the gauntlet from either end by opening the switch 14 or 14', as the case may be, stops the generation of the high frequency current which would cause indications of safety on a car from the opposite direction, and upon the lamp 17 or 17 at the opposite end of the gauntlet. As soon as his car has passed into the gauntlet the trainman closes the switch he had previously opened, but his car now being in-the gauntlet and diverting the high frequency currents to the rails effectively prevents safety conditions being indicated by either of the lamps 17 or 17, or by the green lamp 29 of the cars approaching the gauntlet from either direction.

I might say at this point that while I do notcontemplate that two cars traveling in opposite directions should ever get into the gauntlet at the same time, if such a condition should arise the circuits of each car would be diverting to the rails the high frequency current which normally would cause safety to be indicated on the other car. Thus the red lamps 30 would be lighted on both cars and the driver of each made cognizant of the presence of the other car in the gauntlet.

It will be understood that while I have illustrated the relays 27 and 27 as controlling the circuits for a single pair of green and red signal lamps 29 and 80, I may if I choose have a pair of said lamps under the control of each relay and in such a case it would be unnecessary to provide the switches 32 and 33.

It will .be understood also that while in the annexed claims I refer to a trolley wire as the means for carrying the high freuency currents, I consider wayside conductors and third rails to fall within the scope of my claims in so far as they are capable of accomplishing the purposes of my invention.

Having thus described my invention, what I claim as new and desire to secure by Let ters Patent is:

1. In a system of the class described, a track and a trolley wire section associated with a certain section of said track. means for applying high frequency oscillatory current to said trolley wire section at or near one end thereof, and means for applying high frequency oscillatory current of different frequency to said trolley wire section at or near the opposite end thereof.

2. In a system of the class described, a track and a trolley wire section associated with a certain section of said track, means for applying high frequency oscillatory current to said trolley wire section at or near one end thereof, and means for applying high frequency oscillatory current of different frequency to said trolley wire section at or near the opposite end thereof, together with signal devices at or near each end of said trolley wire section, each of said signaling devices adapted to'be operated by the high frequency current applied at the opposite end of said trolley wire section.

3. In a system of the class described. a track and a trolley wire section associated with a certain section of said track, means for applying high frequency oscillatory current to said trolley wire section at or near one end thereof, and means for applying high frequency oscillatory current of different frequency to said trolley wire section at or near the opposite end thereof. and a car movable on said track provided with signaling devices, one responsive to high frequency oscillatory current of one frequency and the other responsive to high frequency oscillatory currents of the other frequency.

4. In a system of the class described. the combination with a track and a trolley wire. said trolley wire divided into sections. and means for applying high frequency oscillatorv current of different frequencies to the ends of one of said trolley wire sections, together with signaling devices at or near the ends of said trolley wire section, each of the signaling devices adapted to be responsive to the high frequency oscillatory current applied at the opposite end of said trolley wire section.

5. In a system of the class described, the combination of a track and a trolley wire divided into sections. means for applying high .frequency oscillatory current to one of said sponsive to said high frequency oscillatory current. I

6. In a system of the class described, the combination with a track and a trolley Wire, said trolley wire divided into sections, and means for applying high frequency oscillatory current of different frequencies to the ends of one of said trolley wire sections. together with a pair of high frequency oscilla tory current detectors carried by a car movable on said track. signaling devices, and means for placing said signaling devices under the control of either of said detectors.

7. In a system of the class described, a track "nd a trolley wire section associated with a certain section of said track. means for applying high frequency oscillatory cur- .means adapted to be operated to discontinue the application of one of said high frequency currents to said trolley wire when a car is about to enter that part of the track to which said trolley wire section is assigned.

8. In combination with the track and trolley wire of an electric railway system, a car provided with a trolley adapted to connect the car circuits with said trolley Wire, and electricity conducting means normally out of engagement with said trolley wire, arranged and adapted automatically to make contact with the trolley wire and again electrically connect the car circuits with the trolley wire whenever the trolley is disconnected from said trolley wire.

9. In combination with the track and trolley wire of an electric railway system, a car provided with a trolley. adapted to co-operate with said trolleywire electrically to connect the latter with the car circuits.

means carriedby the car normally out of wire. and devices controlled by the current supplied through said trolley normally looking said means out of engagement with the trolley wire but adapted to permit the same to engage the trolley wire whenever the trolley is disengaged from the trolley wire.

10. In an electric railway, a plurality of tracks over which traffic moves in but one direction, said tracks connecting with a gauntlet over which trailic moves in two directions, a trolley wire associated with each of said first-mentioned tracks, and a trolley wire section co-extensive with the gauntlet, means continuously impressing high frequency currentof different frequencies upon the end of the gauntlet trolley wire section, and signaling means connected with the end of the gauntlet trolley wire section, each signaling means being responsive to the high frequency current impressed upon the opposite end of the gauntlet trolley wire section, when there is no car in the gauntlet afl'ording a short circuit for the high frequency current to which said sigwire section co-extensive with the gauntlet,

I trolley.

means continuously impressing high freuency current of different frequencies upon t e ends of the gauntlet trolley wire section, and tuned by-passes connecting the end of the gauntlet trolley wire section with the wires of the tracks first above mentione each by-pass being adjusted to pass current of the articular high frequency imressed upon t e opposite end of the gaunt et trolley wire section, and to exclude the other high frequency current impressed upon the gauntlet trolley wire section.

12. In an electric railway, a plurality of tracks, overwhich trafiic moves in but one direction, said tracks connecting with a gauntlet over which trafiic moves in two directions, a trolley wire associated with each of said first-mentioned tracks, and a trolley wire section co-extensive with the gauntlet, means continuously impressing high frequency current of different frequencies upon the ends of the gauntlet trolley wire section, and tuned by-passes connecting the ends of the gauntlet trolley wire section with the trolley wires of the tracks first above mentioned, each by-pass being adjusted to pass current of the particular high frequency impressed upon the opposite end of the gauntlet trolley wire section, and to exclude the other high frequency current impressed upon the gauntlet trolley wire section, each of said by-passes including a signaling device which indicates safety when there is a high frequency current traversing the byass.

P In witness whereof, I hereunto subscribe my name this 18th day of February, 1919.

' JOHN A. MILLER.

Witnesses:

A. G. MoCALEB, MARY FAE PETRIE. 

